AU where Zuko has Toph for a sister instead of Azula.

attackfish:

Hmm, this is a hard one, because it isn’t one I’ve actually given a whole lot of thought to.  I assume you mean that Toph is the youngest child of Ozai and Ursa?

1.Toph in this verse is a prodigy firebender instead of a prodigy earthbender, but because she’s blind her father thinks she’s weak. This drives her to train harder, and to work to develop ways to “see” with her bending.  This is much more limited than her earth sense, and works like Zuko’s fire sense in Quiet Shadowed Places.

2. Between Toph’s blindness and Zuko’s compassion, Ozai in this verse does not play favorites, because he is too busy believing both his children are completely useless and worthless.  This right here fundamentally changes family dynamics, history, everything.

3. Ozai is constantly pressuring Ursa to have another child, meanwhile, he keeps trying to convince Azulon to let him divorce Ursa and marry a woman who won’t give him such “defective heirs.”  This all comes to a head when Lu Ten dies, and Ozai ends up strangling Azulon himself after Azulon suggests that maybe it’s Ozai that’s the problem.  Then, he pins the murder on Ursa and has her executed.

4. Ozai becomes Firelord, remarries, and gets with the baby making.  As soon as his new wife is pregnant, he starts looking for a way to dispose of his useless older children.  Meanwhile Iroh has all but adopted them.  When he exiles Zuko on a pretext, he accuses Toph of plotting with her brother to dishonor the general and the Firelord, and exiles her as well.

5. Because of this changed dynamic, Zuko’s daddy issues are different from canon.  He still has the intense drive to prove himself, but he does not believe daddy will ever love him, and he is extremely depressed and has low self esteem.  Meanwhile, Toph’s intense need to prove herself leads to recklessness.  Between the two of them, Iroh has started to go bald from pulling his hair out.  Instead of looking for the Avatar, however, Iroh has convinced them to settle down in the colonies with him.  This is when the Avatar finds them, or more precisely, when the Order of the White Lotus sends the Avatar to them.